Judge Coyle ordered the woman's interim name suppression to continue.
The court heard that on March 7 the woman fired a shotgun into a house near Bellevue School.
She then walked towards the school and was seen reloading before firing the gun into school grounds. Pellets were later found in school bushes. A witness called 111 and the schools went into lockdown.
The court also heard that when the woman was asked why she fired the shotgun, belonging to her partner, she said: "I just pulled the trigger. It went off, it gave me a fright. I've had a bad week."
Judge Coyle said the woman was remorseful and took into account personal circumstances when he jailed her for 12 months.
However, he referred to the panic and fear instilled in the school community, some of whom would have been thinking they were about to become victims of a mass school shooting.
Shortly after the incident, an Otumoetai College student told the Bay of Plenty Times that students at the school "thought we'd die for a while ... [I'm] still a little traumatised".
Children were sitting in darkness below window height as the woman was tracked down.
Dozens of distressed parents waited outside the primary school to be given the all-clear to pick up their children. Some parents, who were walking their children to school at the time, reported hearing at least two shots fired near the school.
Police applauded the prompt response from the schools and Montessori Otumoetai.